The invention relates generally to monitoring the system environment of an inactive networked computer, and more specifically to monitoring network activity for specific events.
Local Area Networks (LAN""s) consist of a group of interconnected computers communicating according to a common protocol such as Ethernet (IEEE Standard 802.3). In a client-server type LAN, a server computer maintains files, which may be accessed by client computers. The server may also monitor and perform various maintenance functions on the client computer.
To save energy and reduce costs, client computers may enter a reduced-power (or sleep) state when they are not in active use. A sleep-state shuts-down most components of a client computer and maintains only minimal functionality. Various techniques have been implemented to allow a server computer to wake-up a sleeping client computer. Generally these techniques require the sleeping computer to monitor network activity.
For this purpose, some network interfaces provide a hardware state machine which is configured to monitor for specific bit patterns when the computer enters a sleep state. This allows the network interface to detect specific network events, however configuration is generally fixed. Accordingly, network interfaces having a hardware state machine may not be easily reconfigured to meet the needs of a specific application.
Other solutions may use a standard MAC accessing a direct memory access (DMA) first-in first-out (FIFO) memory for receiving network frame data. Frame data saved to the system memory may be parsed to detect specific bit patterns. These interfaces provide greater flexibility. Specifically, these interfaces may be programmed to monitor for different bit patterns depending upon the application. Unfortunately, these interfaces likewise impose greater cost and complexity.
According to one aspect of the invention a network interface suitable for receiving frame data over a network includes a media access control, a buffer manager, and a memory. The media access control provides a connection to a media interface. The buffer manager is operationally coupled with the media access control and is configured to receive frame data from the media access control. The memory has a plurality of segments, which are operationally coupled with the buffer manager. The buffer manager is configured to write the frame data to the memory segments.
According to another aspect of the invention, a receive buffer memory has a plurality of segments. The receive buffer memory receives first and second frame data from a network. The receive buffer memory writes the first frame data to a first segment of the receive buffer memory and writes the second frame data to a second segment of the receive buffer memory. The receive buffer memory also reads the first frame data from the first segment of the receive buffer memory simultaneous the writing of the second frame data.
According to another aspect of the invention, a controller suitable for monitoring events related to a computer system includes a control processor, a plurality of connections, and a network interface. The control processor is configured to communicate with a host processor. The plurality of connections are operationally coupled with the control processor. The control processor is configured to monitor system events over the plurality of connections. The network interface is operationally coupled with the control processor and has a memory partitioned into a plurality of segments. The segments provide frame data to the control processor. The control processor is configured to monitor network events from the frame data.
According to another aspect of the invention, a computer system has a network connection. The computer system enters a reduced power state. The computer system receives a plurality of frames from a network. The computer system filters the plurality of frames. The computer system writes first frame data from the plurality of frames to a first segment of a receive buffer memory. The computer system reads the first frame data from the first segment of the receive buffer memory.
These and other objects, features and advantages will become apparent when considered with reference to the following description and the accompanying drawings.